Alterations In Fatty Acid Composition Research Articles

Linking Above- and Belowground Responses to 16 Years of Fertilization, Mowing, and Removal of the Dominant Species in a Temperate Grassland

Species-rich oligotrophic meadows are affected by a wide range of management interventions that influence their functioning and capacity to deliver ecosystem services, but long-term studies on the above- and belowground adaptations to different management tools are still scarce. We focused on the interactive effects of NPK fertilization, mowing, and removal of the initially dominant species (Molinia caerulea) on plant, soil, and microbial responses in wet oligotrophic grassland in a 16-year full-factorial manipulative experiment. Changes in vegetation composition, soil pH, and nutrient availability were accompanied by altered microbial phospholipid fatty acid (PLFA) composition, whereas treatment effects on soil microbial biomass and carbon (C) mineralization were mainly related to changes in soil organic matter (SOM) content and nutrient availability. Fertilization decreased plant species richness aboveground and lowered SOM storage and microbial activity belowground. Mowing preserved high plant diversity and led to more efficient recycling of N within the grassland, whereas Molinia removal significantly affected only plant community composition. Mowing combined with fertilization maintained high species richness only in the short term. Belowground, mowing reduced N leaching from the fertilized system but did not prevent SOM depletion, soil acidification, and concomitant adverse effects on soil microbes. We conclude that annual mowing is the appropriate type of extensive management for oligotrophic species-rich meadows, but the concomitant nutrient depletion should not be compensated for by regular NPK fertilization due to its adverse effects on soil quality.

Functional roles of the fatty acid desaturases encoded by KlOLE1, FAD2 and FAD3 in the yeast Kluyveromyces lactis.

Functional properties of cell membranes depend on their composition, particularly on the relative amount of saturated, unsaturated and polyunsaturated fatty acids present in the phospholipids. The aim of this study was to investigate the effect of cell membrane composition on cell fitness, adaptation and stress response in Kluyveromyces lactis. To this purpose, we have deleted the genes FAD2 and FAD3 encoding Δ12 and ω3 desaturases in Kluyveromyces lactis, thus generating mutant strains with altered fatty acid composition of membranes. These strains were viable and able to grow in stressing conditions like hypoxia and low temperature. Deletion of the Δ9 desaturase-encoding gene KlOLE1 resulted in lethality, suggesting that this enzyme has an essential role in this yeast. Transcription of the desaturase genes KlOLE1, FAD2 and FAD3 and cellular localization of the corresponding enzymes, have been studied under hypoxia and cold stress. Our findings indicate that expression of these desaturase genes and membrane composition were modulated by hypoxia and temperature stress, although the changes induced by these and other assayed conditions did not dramatically affect the general cellular fitness.

Regulation And Function Of Fatty Acid Desaturases

Stearoyl‐CoA desaturase is a central lipogenic enzyme catalyzing the synthesis of monounsaturated fatty acids mainly oleate (C18:1) and palmitoleate (C16:1) which are the major monounsaturated fatty acids of membrane phospholipids, triglycerides, wax esters and cholesterol esters. Several SCD gene isoforms (SCD1‐4) exist in the mouse. While SCD1, 2 and 4 desaturate both 16:0 and 18:0 to 16:1n7 and 18:1n9 respectively, the SCD3 isoform has a substrate specificity and prefers desaturation of 16:0 to 16:1n7. 16:1n7 has been labeled as a lipokine that represses hepatic de novo lipogenesis and improves insulin signaling in muscle. We found that mice with a targeted disruption of the SCD3 isoform (SCD3−/−) exhibit dramatic brown adipose tissue (BAT) expansion and whitening with paradoxical increase in monounsaturated fatty acids and triglyceride accumulation. The alteration in fatty acid composition and lipid metanbolism causes reduced abundance of electron transport chain components and near ablation of UCP1 in BAT. Interestingly, this decreased protein abundance is not driven by repressed gene transcription and likely stems from protein instability and degradation. Consequently, the SCD3−/− mice have impaired cold tolerance and cannot maintain core body temperature during a 4ºC cold challenge past 6 hours. Meanwhile, the subcutaneous WAT of the KO mice shows increased expression of genes associated with fatty acid oxidation and thermogenesis. These observations suggest that SCD3 expression plays distinct roles in BAT and subcuteneous fat depots and help to elucidate how changes in monounsaturated fatty acids modulate metabolic activities in adipocytes.Support or Funding InformationSupported by NIH grants RO1DK62388 and T32 GM07215.

Manipulation of milk fatty acid composition in lactating cows: Opportunities and challenges

Public health policies recommend a population wide decrease in the consumption of saturated fatty acids (SFA) to lower the incidence of cardiovascular and metabolic diseases. In most developed countries, milk and dairy products are the major source of SFA in the human diet. Altering milk fat composition offers the opportunity to lower the consumption of SFA without requiring a change in eating habits. Supplementing the diet of lactating cows with oilseeds, plant oils and marine lipids can be used to replace the SFA in milk fat with monounsaturated fatty acids (MUFA), and to a lesser extent, polyunsaturated fatty acids (PUFA). Due to ruminal metabolism, the decreases in milk SFA are also accompanied by increases in trans fatty acids (TFA), including conjugated isomers. The potential to lower SFA, enrich cis MUFA and PUFA, and alter the abundance and distribution of individual TFA in milk differs according to oil source, form of lipid supplement and degree of oilseed processing, and the influence of other components in the diet. The present review summarises recent evidence on changes in milk fat composition that can be achieved using dietary lipid supplements and highlights the challenges to commercial production of modified milk and dairy products. A meta‐analysis on the effects of oilseeds on milk fatty acid composition is also presented.Practical applications: Milk and dairy products are the major source of SFA in the diet in most developed countries. Including oilseeds, plant oils, and to a lesser extent, marine lipids in the diet of lactating cows can replace SFA with MUFA and PUFA in milk offering a mechanism to lower SFA consumption in human populations. Understanding the sources of variation in milk fat composition responses, and adjusting other ingredients in the diet to accommodate lipid supplements offers the opportunity to consistently produce milk with an altered fatty acid composition. However, commercialisation of dedicated supply chains will depend on whether the added costs of production and segregation of modified milk for processing can be recovered at retail.Dairy products are the major source of saturated fatty acids in diets of developed countries. There are various dietary strategies that can be employed at the dairy cow level to alter milk fat fatty acid composition, but it is important to understand variations in cow response to these interventions to consistently produce milk with altered fatty acid composition.

Modification of oil and glucosinolate content in canola seeds with altered expression of Brassica napus LEAFY COTYLEDON1

Over the last few decades, research focusing on canola (Brassica napus L.) seed oil content and composition has expanded. Oil production and accumulation are influenced by genes participating in embryo and seed development. The Arabidopsis LEAFY COTYLEDON1 (LEC1) is a well characterized regulator of embryo development that also enhances the expression of genes involved in fatty acid (FA) synthesis. B. napus lines over-expressing or down-regulating BnLEC1 were successfully generated by Agrobacterium-mediated transformation. The constitutive expression of BnLEC1 in B. napus var. Polo, increased seed oil content by 7–16%, while the down-regulation of BnLEC1 in B. napus var. Topas reduced oil content by 9–12%. Experimental manipulation of BnLEC1 caused transcriptional changes in enzymes participating in sucrose metabolism, glycolysis, and FA biosynthesis, suggesting an enhanced carbon flux towards FA biosynthesis in tissues over-expressing BnLEC1. The increase in oil content induced by BnLEC1 was not accompanied by alterations in FA composition, oil nutritional value or glucosinolate (GLS) levels. Suppression of BnLEC1 reduced seed oil accumulation and elevated the level of GLS possibly through the transcriptional regulation of BnST5a (Sulphotransferase5a), the last GLS biosynthetic enzyme. Collectively, these findings demonstrate that experimental alterations of BnLEC1 expression can be used to influence oil production and quality in B. napus.

Association of fatty acid metabolism with systemic inflammatory response in chronic respiratory diseases

We examined composition of plasma non-esterified fatty acids (NFAs), erythrocyte fatty acids, levels of eicosanoids in patients with asthma and chronic obstructive pulmonary disease (COPD) with different type of the inflammatory response. The results of our study show that asthma and COPD in remission are associated with changes in the composition NFAs of plasma, FA of erythrocytes, level eicosanoid despite the difference in the regulation of immunological mechanisms of systemic inflammation. These changes are characterized by excessive production of arachidonic acid (20:4n-6) and cyclooxygenase and lipoxygenase metabolites (thromboxane B2, leukotriene B4) and deficiency of their functional antagonist, eicosapentaenoic acid (20:5n-3). The recognized association between altered fatty acid composition and disorders of the immune mechanisms of regulation of systemic inflammation in COPD and asthma demonstrated the important role of fatty acids and their metabolites in persistence of inflammatory processes in diseases of the respiratory system in the condition of remission.

Overexpression of the olive acyl carrier protein gene (OeACP1) produces alterations in fatty acid composition of tobacco leaves.

Taking into account that fatty acid (FA) biosynthesis plays a crucial role in lipid accumulation in olive (Olea europaea L.) mesocarp, we investigated the effect of olive acyl carrier protein (ACP) on FA composition by overexpressing an olive ACP cDNA in tobacco plants. The OeACP1.1A cDNA was inserted in the nucleus or in the chloroplast DNA of different tobacco plants, resulting in extensive transcription of the transgenes. The transplastomic plants accumulated lower olive ACP levels in comparison to nuclear-transformed plants. Moreover, the phenotype of the former plants was characterized by pale green/white cotyledons with abnormal chloroplasts, delayed germination and reduced growth. We suggest that the transplastomic phenotype was likely caused by inefficient olive ACP mRNA translation in chloroplast stroma. Conversely, total lipids from leaves of nuclear transformants expressing high olive ACP levels showed a significant increase in oleic acid (18:1) and linolenic acid (18:3), and a concomitant significant reduction of hexadecadienoic acid (16:2) and hexadecatrienoic acid (16:3). This implies that in leaves of tobacco transformants, as likely in the mesocarp of olive fruit, olive ACP not only plays a general role in FA synthesis, but seems to be specifically involved in chain length regulation forwarding the elongation to C18 FAs and the subsequent desaturation to 18:1 and 18:3.

Altered serum fatty acid composition in geriatric depression.

Fatty acids (FA), mainly polyunsaturated (PUFA) of n-3 or n-6 types, may influence neuropsychobiological processes. Decreased levels of n-3 PUFA have been shown to be related to major depression and supplementation of n-3 PUFA seems to contribute to improved depression treatment outcome. The profiles of serum FA profiles in patients with geriatric depression have not been thoroughly studied yet. The present study investigated the FA profiles of patients with geriatric depression and of mentally healthy elderly individuals. Serum FA profiles of 36 inpatients with geriatric depression who fulfilled DSM-IV criteria for unipolar major depression were compared with those of 37 control subjects. Patients with geriatric depression, irrespective of gender, exhibited lower total FAs, as well as significantly lower concentrations of total n-3 PUFA and eicosapentaenoic acid, though the groups did not differ with regard to Body Mass Index. The findings of the present study point to an association between lower FA serum levels and geriatric depression. Further investigations with larger samples and dietetic interventions may provide deeper insights into the role of eicosapentaenoic acid and total n-3 PUFA in the development and treatment of geriatric depression.

Metabolic engineering toward enhanced LC-PUFA biosynthesis in Nannochloropsis oceanica: Overexpression of endogenous Δ12 desaturase driven by stress-inducible promoter leads to enhanced deposition of polyunsaturated fatty acids in TAG

Nannochloropsis oceanica is an important source for omega-3 long-chain polyunsaturated fatty acids (LC-PUFA) such as eicosapentaenoic acid (EPA, 20:5 n−3), and a potent candidate for biofuel production, due to its outstanding capability for rapid induction of triacylglycerol (TAG) overproduction. In contrast to membrane lipids, TAG of N. oceanica is poor in the valuable LC-PUFA, EPA. We identified, cloned and characterized a N. oceanica microsomal-like Δ12-desaturase (NoD12) mediating the committing step of LC-PUFA biosynthesis by converting oleic acid (18:1 n−9) to linoleic acid (LA,18:2 n−6). We generated strains of N. oceanica overexpressing NoD12 under the control of the stress-inducible endogenous lipid droplet surface protein (LDSP) promoter, resulting in robust expression under nitrogen starvation conditions. The overexpression of NoD12 significantly altered fatty acid composition of total lipids and of individual lipid classes, such as a drastic increase in 18:2 proportion in phosphatidylcholine and in TAG was observed under nitrogen starvation. Some LA was converted further toward LC-PUFA resulting in a substantial increase in arachidonic acid (20:4 n−6) in TAG. Our data demonstrate the feasibility of metabolic engineering to increase LC-PUFA content in the biotechnologically important microalga using native genes and promoters, and provide novel insights into the regulation of LC-PUFA flux to TAG under nitrogen starvation.

Genetic and Environmental Effects on Fatty Acid Composition in Soybeans with Potential Use in the Automotive Industry

ABSTRACTEnvironmental effects on quantitative traits such as seed oil fatty acid composition in soybean [Glycine max (L.) Merrill] can significantly affect the performance of a given genotype when exposed to varying growing conditions. High linoleic acid oils have the potential to be used as raw materials for the production of polyols and polyurethane that can be used in the automotive industry. The objectives of this study were (i) to determine the sources of variation affecting seed oil fatty acids profiles and (ii) to evaluate stability of soybean genotypes with different fatty acids across different environments. Fifty‐six soybean genotypes with altered fatty acid composition selected from two recombinant inbred line populations segregating for saturated and linoleic acids were used along with commercial high yielding cultivars. All genotypes were evaluated in southwestern Ontario, Canada, at three locations in 2008 and two locations in 2009, and data was collected for fatty acid composition as well as other seed and agronomic traits. Combined analysis of variances showed significant location and genotype × location effects for stearic and oleic acids. Genotype × environment effect was significant for unsaturated fatty acids plus seed oil and protein concentrations. The effect of genotype × year was significant for unsaturated fatty acids. Stability analyses using Francis and Kannenberg's mean coefficient of variation stability, Shukla's stability variance statistic (σ2), and Lin and Binns cultivar superiority measure identified genotypes E‐49 and E‐14 as being superior for high linoleic and low saturated fatty acids oil production for potential use in the automotive industry.

ENO2 activity is required for the development and reproductive success of plants, and is feedback-repressed by AtMBP-1.

Enolases are key glycolytic enzymes that are highly conserved in prokaryotic and eukaryotic organisms, and are among the most abundant cytosolic proteins. In this study we provide evidence that activity of the enolase ENO2 is essential for the growth and development of plants. We show that Arabidopsis plants with compromised ENO2 function, which were generated by mutating the LOS2/ENO2 locus, have severe cellular defects, including reduced cell size and defective cell differentiation with restricted lignification. At the tissue and organ level LOS2/ENO2-deficient plants are characterized by the reduced growth of shoots and roots, altered vascular development and defective secondary growth of stems, impaired floral organogenesis and defective male gametophyte function, resulting in embryo lethality as well as delayed senescence. These phenotypes correlate with reduced lignin and increased salicylic acid contents as well as altered fatty acid and soluble sugar composition. In addition to an enolase the LOS2/ENO2 locus encodes the transcription factor AtMBP-1, and here we reveal that this bifunctionality serves to maintain the homeostasis of ENO2 activity. In summary, we show that in plants enolase function is required for the formation of chorismate-dependent secondary metabolites, and that this activity is feedback-inhibited by AtMBP-1 to enable the normal development and reproductive success of plants.

Age-dependent biochemical dysfunction in skeletal muscle of triple-transgenic mouse model of Alzheimer`s disease.

The emergence of Alzheimer`s disease as a systemic pathology shifted the research paradigm toward a better understanding of the molecular basis of the disease considering the pathophysiological changes in both brain and peripheral tissues. In the present study, we evaluated the impact of disease progression on physiological relevant features of skeletal muscle obtained from 3, 6 and 12 month-old 3xTg-AD mice, a model of Alzheimer`s disease, and respective agematched nonTg mice. Our results showed that skeletal muscle functionality is already affected in 3-month-old 3xTg-AD mice as evidenced by deficient acetylcholinesterase and catalase activities as well as by alterations in fatty acid composition of mitochondrial membranes. Additionally, an age-dependent accumulation of amyloid-β1-40 peptide occurred in skeletal muscle of 3xTg-AD mice, an effect that preceded bioenergetics mitochondrial dysfunction, which was only detected at 12 months of age, characterized by decreased respiratory control ratio and ADP/O index and by an impairment of complex I activity. HPLC-MS/MS analyses revealed significant changes in phospholipid composition of skeletal muscle tissues from 3xTg-AD mice with 12 months of age when compared with age-matched nonTg mice. Increased levels of lyso-phosphatidylcholine associated with a decrease of phosphatidylcholine molecular species containing arachidonic acid were detected in 3xTg-AD mice, indicating an enhancement of phospholipase A2 activity and skeletal muscle inflammation. Additionally, a decrease of phosphatidylethanolamine plasmalogens content and an increase in phosphatidylinositol levels was observed in 3xTg-AD mice when compared with age-matched nonTg mice. Altogether, these observations suggest that the skeletal muscle of 3xTg-AD mice are more prone to oxidative and inflammatory events.

The disruption of prenylation leads to pleiotropic rearrangements in cellular behavior in Staphylococcus aureus.

Prenylation is the addition of prenyl groups to peptide chains or metabolites via the condensation of geranyl- or isopentenyl-diphosphate moieties by geranyltranstransferases. Although this process is extensively studied in eukaryotes, little is known about the influence of prenylation in prokaryotic species. To explore the role of this modification in bacteria, we generated a mutation in the geranyltranstransferase (IspA) of Staphylococcus aureus. Quite strikingly, the ispA mutant completely lacked pigment and exhibited a previously undescribed small colony variant-like phenotype. Further pleiotropic defects in cellular behavior were noted, including impaired growth, decreased ATP production, increased sensitivity to oxidative stress, increased resistance to aminoglycosides and cationic antimicrobial peptides, and decreased resistance to cell wall-targeting antibiotics. These latter effects appear to result from differences in envelope composition as ispA mutants have highly diffuse cell walls (particularly at the septum), marked alterations in fatty acid composition and increased membrane fluidity. Taken together, these data present an important characterization of prokaryotic prenylation and demonstrate that this process is central to a wealth of pathways involved in mediating cellular homeostasis in S. aureus.

Omega‐3 fatty acid supplementation candidates can be selected using fatty acid profiling

The aim of this study was to evaluate the fatty acid (FA) profile in the plasma and erythrocyte membranes of apparently healthy men compared to male patients with various cardiovascular diseases (CVD). The plasma FA profiles were analyzed in five groups of subjects aged 37–57 years: groups 1 and 2 were male voluntary blood donors with a body mass index (BMI) 25.1 ± 1.6, (Group 1, N = 12) and a BMI 32.9 ± 4.5, (Group 2, N = 11) respectively, male patients with chronic heart failure due to dilated cardiomyopathy (Group 3, N = 10), chronic atrial fibrillation without heart failure or coronary heart disease (Group 4, N = 10) and patients after myocardial infarction (Group 5, N = 11). The FA profile in plasma and erythrocytes was measured by gas chromatography (GC) with flame ionization detection and basic plasma lipid parameters were then estimated. Deficiencies of eicosapentaenoic acid and docosahexaenoic acid were found in all the groups of CVD patients and in Group 2 (BMI 32.9 ± 4.5) of this Central European population. Unfavorable alterations in FA composition and clinical biochemistry parameters were found in patients with dilated cardiomyopathy (Group 3). Further, 75% of Group 1 (blood donors) had an average plasma PUFA level in the worst quartile for relative risk of cardiovascular events. Tailored n‐3 PUFA supplementation should be recommended not only for secondary prevention in patients suffering from CVD but also for primary prevention in overweight and obese persons with a proven deficiency.Practical applications: Plasma and erythrocyte membrane n‐3 polyunsaturated fatty acid (PUFA) levels are an important parameter of diet composition as well as a marker of cardiovascular risk. Regular sea fish intake or alternative supplementation with the n‐3 PUFA recommendation is in all probability insufficiently realized, particularly in inland countries. In addition to contemporary guidelines and practice, research is providing data on the use of FA analysis for revealing people with an n‐3 PUFA deficiency. This approach could benefit people suffering from CVD as well as for overweight and obese populations with demonstrated deficiency.Tailored n‐3 PUFA supplementation should be recommended not only for secondary prevention in patients suffering from CVD but also for primary prevention in overweight and obese persons with a proven deficiency.

Impact of temperature on the expression of Kennedy Pathway genes in developing soybean seeds

McNaughton, A. J. M., Shelp, B. J. and Rajcan, I. 2015. Impact of temperature on the expression of Kennedy Pathway genes in developing soybean seeds. Can. J. Plant Sci. 95: 87-101. The main oil storage molecule, triacylglycerol (TAG), can be created by the Kennedy Pathway. The objective of this study was to determine the impact of growing temperature on the expression of the Kennedy Pathway genes, glycerol-3-phosphate acyltransferase (G3PAT), lysophosphatidic acid acyltransferase (LPAAT), and diacylglycerol acyltransferase 1 (DGAT1), in developing seed of four soybean genotypes with altered fatty acid composition using quantitative polymerase chain reaction. The three growing temperatures were: high, 30°C day/25°C night; normal, 25°C day/20°C night; and low, 20°C day/15°C night. The expression of G3PAT steadily declined following 15 d after flowering (DAF), suggesting that it is likely to be more highly expressed earlier in development than was measured in the study. As a result, the expression of G3PAT d...

Impact of temperature on the expression of Kennedy Pathway genes in developing soybean seeds

McNaughton, A. J. M., Shelp, B. J. and Rajcan, I. 2015. Impact of temperature on the expression of Kennedy Pathway genes in developing soybean seeds. Can. J. Plant Sci. 95: 87–101. The main oil storage molecule, triacylglycerol (TAG), can be created by the Kennedy Pathway. The objective of this study was to determine the impact of growing temperature on the expression of the Kennedy Pathway genes, glycerol-3-phosphate acyltransferase (G3PAT), lysophosphatidic acid acyltransferase (LPAAT), and diacylglycerol acyltransferase 1 (DGAT1), in developing seed of four soybean genotypes with altered fatty acid composition using quantitative polymerase chain reaction. The three growing temperatures were: high, 30°C day/25°C night; normal, 25°C day/20°C night; and low, 20°C day/15°C night. The expression of G3PAT steadily declined following 15 d after flowering (DAF), suggesting that it is likely to be more highly expressed earlier in development than was measured in the study. As a result, the expression of G3PAT did not correspond to fatty acid accumulation. LPAAT expression coincided with accumulation of oleic acid (18:1∆9) and linolenic acid (18:3∆9,12,15) in a temperature-dependent manner. The expression of DGAT1 corresponded to accumulation of linoleic acid (18:2∆9,12), which varied among the soybean genotypes, indicating a genotypic effect on the expression of DGAT1. This study suggests that the expression of the acyltransferase enzymes of the Kennedy Pathway influences the fatty acid composition in seed of four altered fatty acid soybean genotypes.

Fatty acid content in muscles of amago salmon homozygous or heterozygous for a growth hormone transgene

Abstract Fatty acids are a vital energy source in fish and are of significant importance to their physiological wellbeing. Amago salmon ( Oncorhynchus masou ishikawae ) transgenic for a growth hormone (GH) show both accelerated growth and altered fatty acid composition and content in liver tissues. In particular, they show a decrease in saturated fatty acids and monounsaturated fatty acids, and an increase in polyunsaturated fatty acids except for docosahexaenoic acid (22:6n− 3) and eicosapentaenoic acid (20:5n − 3). Furthermore, transgenic fish have decreased levels of serum glucose, triacylglycerol and an increase in 3-hydroxybutyric acid, generally considered a starvation marker. As liver tissue is physiologically connected to muscle tissue, here we examined the effects of GH transgenesis on fatty acid contents in muscles of homozygous and heterozygous GH transgenic fish. The major monounsaturated fatty acids oleic acid (18:1n − 9) and palmitoleic acid (16:1n − 7) were slightly higher in the control, whereas polyunsaturated fatty acids, except 22:6n − 3 and 20:5n − 3, were significantly greater in the transgenic fish ( P P

Abstract 4959: High-resolution MALDI imaging mass spectrometry demonstrated the correlation between phosphatidylinositol profiles and invasion/metastasis in human breast cancer

Abstract High-resolution matrix-assisted laser desorption/ionization imaging mass spectrometry (HR-MALDI IMS) is an emerging application for lipid research that provides a detailed histological distribution of ionized lipids within tissue section. Phosphatidylinositol (PI) is one of the major classes of membrane phospholipid. The cellular membrane fluidity and signal transduction activity could be modulated by the alteration of fatty acid composition of PIs. Especially, PI-3kinase pathway, which can be activated by the phosphorylation of PIs, has become a great concern in breast cancer treatment. Although the amount of PIs is known to increase in human breast cancer tissues, it remains unclear how PIs are distributed in cancerous tissues. In this study, we investigated the detailed spatial distribution of PIs in breast tissues obtained from 24 patients, including 23 invasive ductal carcinoma (IDC), 4 ductal carcinoma in situ (DCIS), and 4 fibrocystic change lesions by using HR-MALDI IMS. The distribution of PIs was visualized at the resolution of 10um. 10 PIs with different fatty acid composition were detected in breast tissues. High-resolution analysis revealed the fatty acid composition of PIs was altered specifically in cancer cell clusters compared to stromal cells and non-malignant epithelia. PIs carrying monounsaturated fatty acid (MUFA) and PIs carrying polyunsaturated fatty acid (PUFA) showed the specific localization to cancer cell clusters. However, the proportion of PIs carrying MUFA and PIs carrying PUFA showed a clear inverse correlation in cancer cells. When we compared the PI profiles of IDC, DCIS, and FC, it was suggested that the accumulation of PIs carrying PUFA was occurred during the step of invasion. Moreover, lymph node metastasis well correlated with the accumulation of PIs carrying PUFA in cancer cells. HR-MALDI IMS firstly demonstrated the possible association between the PI profiles of breast cancer cells and their invasion/metastasis ability. Although this is a preliminary study, HR-MALDI IMS could be a useful modality to visualize the reprogramming of the lipid metabolism which reflects the cancer cell phenotype. Citation Format: Masahiro Kawashima, Nobuko Kawaguchi-Sakita, Masahiro Sugimoto, Taka-Aki Sato, Koichi Tanaka, Masakazu Toi. High-resolution MALDI imaging mass spectrometry demonstrated the correlation between phosphatidylinositol profiles and invasion/metastasis in human breast cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4959. doi:10.1158/1538-7445.AM2014-4959

Lipidomic analysis of fatty acids in erythrocytes of coeliac patients before and after a gluten-free diet intervention: a comparison with healthy subjects

Coeliac disease (CD) patients may exhibit a pro-inflammatory profile and fatty acids (FA) can influence inflammation through a variety of cellular pathways in them. The aims of the present study were to (1) evaluate the FA composition of erythrocytes obtained from newly diagnosed CD patients by lipidomic analysis and compare it with that in healthy subjects and (2) determine the effects of 1-year gluten-free diet (GFD) intervention. A total of twenty CD patients (five men and fifteen women; mean age 34.0 (sem 1.7) years) were evaluated at diagnosis and after 1 year of GFD intervention. A total of twenty healthy subjects (seven men and thirteen women; mean age 40.2 (sem 2.5) years) served as controls. CD patients on an unrestricted diet exhibited a significant 2.08-fold higher concentration of arachidic acid when compared with healthy subjects, suggesting that it can be considered as a putative marker of CD. Besides, the arachidonic acid (AA):dihomo-γ-linolenic acid ratio was 2.01-fold significantly lower in CD patients than in healthy subjects (P< 0.01), underlying an inefficient synthesis of PUFA from their precursors in terms of desaturase activity. In addition, mainly due to lower concentrations of docosahexaenoic acid, the inflammation marker AA:docosahexaenoic acid ratio was 1.40-fold significantly higher in CD patients than in healthy subjects. After 1 year of GFD intervention, FA concentrations in CD patients were still different from those observed in healthy subjects. The lipidomic analysis of erythrocyte membranes confirmed the presence of an altered FA composition in CD patients and the GFD's ability to modify FA profile, even if 1-year GFD intervention seems to be not sufficient to restore FA concentrations to normality. This procedure, being easier and non-invasive compared with the evaluation of the FA pattern of the intestinal mucosa, could offer more potentiality for also evaluating therapeutic interventions in CD patients by using FA supplementation.

Proteomic analysis of MG132-treated germinating pollen reveals expression signatures associated with proteasome inhibition.

Chemical inhibition of the proteasome has been previously found to effectively impair pollen germination and tube growth in vitro. However, the mediators of these effects at the molecular level are unknown. By performing 2DE proteomic analysis, 24 differentially expressed protein spots, representing 14 unique candidate proteins, were identified in the pollen of kiwifruit (Actinidia deliciosa) germinated in the presence of the MG132 proteasome inhibitor. qPCR analysis revealed that 11 of these proteins are not up-regulated at the mRNA level, but are most likely stabilized by proteasome inhibition. These differentially expressed proteins are predicted to function in various pathways including energy and lipid metabolism, cell wall synthesis, protein synthesis/degradation and stress responses. In line with this evidence, the MG132-induced changes in the proteome were accompanied by an increase in ATP and ROS content and by an alteration in fatty acid composition.